Improvement in operating-cocks for fluid-pressure brakes



G. WES'TINGHOUSE, Jr. r Operating Cook forl Fluid-Pressure Brakes.

No. 222,803. Patented Dec. 23,1879.

. m mm .m nYR parts- UNITED STATES N PATENT Ormea GEORGE WESTINGHOUSE,JR., OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN OPERATING-COCKS FR FLUID-PRESSURE BRAKES.

`Specification forming part of Letters Patent N0.`V222,S03,"datedDecember 23, 1879; application filed Y November 10, 1879.

To all whom it may concern.'

Be it known that I, GEORGE W Es'rnvcr HOUSE, Jr., of Pittsburg, countyof Allegheny, State of Pennsylvania, have invented or discovered a newand useful Improvementin Operating-(locks for Fluid-Pressure Brakes; andI do hereby declare the following to be a full, clear, concise, andexact description of the invention, reference being had to theaccompanying drawings, making a part of this specitication, in which-like letters indicating like Figures l and Zare sectional views,`indit'- ferent planes, of a cock in diit'erent positions of adjustment,illustrative ot' the present invention and its manner of operation.

The device shown in the drawings, taken as a wholeVI term a cock, partlyfor convenience, and partly because it is intended, `in a steam-pressurebrake, to take the place and perform the functions ot' the operati ng-cock in a compressed-air brake, which functions are, in the presentcase, to admit the Huid-pressure to the brake-pipes and cylinders fastor slow, as may be desired, to cut ott automatically or stop suchadmission of duid-pressure, to hold or retain automatically suchpressure with little or no increase or diminution,'and also to permitthe escape of the huid-pressure previously admitted or charged into thebrakecylinders; and it is important, for convenience in use, that' allthese functions be performed by movements ot' a single stem, handle,lever, oncrank, so that, so far as the working ot' the brake isconcerned, the engineer need give his attention to but a single device;and itis also of some practical importance, in connection with the useof steam, that all moving parts having an outside connection be packedor made permanently steam-tight, or nearly so, which, with the ordinaryrotating cock, plug, or key, it is somewhat difficult to do.

In the drawings, A represents a case or shell having ears A, orequivalent means, by which to make attachment with any suitable support.In the lower end of the case is a chamber, a, having a ported`diaphragm, a', such as is common in the valve-chambers of globe-valves,but having its valve-seat on the under side, as shown. From this chambera, below the diaphragm af, connection is made by port B and pipe Bwiththe boiler, and from the chamber above the diaphragm a port, B2, andpipe Blead to and through the usual brake-pipe to the brake-cylinders.

The upper part ot' the case Ais cored or chambered out7 substantially asshown, sc asy ner as to give an annular port or chamber, D ,L

extending around it, inside the shell, and with a series of ports, c,leading thereto from an i annular chamber, c', made inside the bushing,

the chamber D opening on one side into-a pipe, D2, which leads to theexternal atmosphere.

The bushing is made with two valve-seats, c2 c3, one above and one belowthe annular chamber c', and on these seats, with a short range orvertical motion therefrom, is avalve, D4, having correspondingseating-faces c f. This valve is kept to its seats partly by its owngravity and partly bya preponderance ot fluidpressure on its upper end,(that end being the larger,) and is raised from its seats by meanspresently to be described.

The upper end ofthe shell A is closed, or rather lengthened, by theextension A2, the lower end of which is bored out, so as to act as aguide to the piston-head I), the enlarged part P of the piston-stemplaying therein, and a screw-thread of steep pitch being provided in itsupper end,

A hollow exteriorly-threaded screwplug, S, is worked inside theextension A2 by means of a crank-arm, S. A shoulder or collar, s, ismade in the inside ofthe upper end of the cavity of the screw-plug S, sotha-t the stem p of the piston-head P passing through may be secured bya pin, si', which extends through the stem, and the ends of which swivelon top of the collar s.

A spring, s2, is arranged between the collar s and the base end ot' theenlargement P', so as to operate with a pushing force in thedirection ofits length.

lt will thus be seen that the screw-plug S may be rotated withoutcausing the rotation` the train is in running condition.

2 :masas of the piston-head P 5 but the stem p extends below thepiston-head, as shown at p', and passes through the valve D, and for alittle distance below the valve, and in fact far enough to abutagainstthe stem e of the valve c, which latter has a seat in the port of thediaphragm a. A pin, a, passes through the stem p' a short distance belowthe lower end of the valve D4, and a collar or washer, n', is arrangedon the stem above the pin.

The valve c is held up to its seat partly by Huid-pressure actingbeneath it and partly by a spring, e2, and it is guided in its motion byits stems c c3. rPhe stems e an'd p' are grooved Vin the direction oftheir length, or made wingshaped in horizontal cross-section, orotherwise so shaped that when the valve e is unseated fluid-pressure maypass freely from a to a2 beneath the piston-head P, as well as to thebrake-cylinders. The ends of the device are closed by screw-caps K K 5but in the npper screw-cap, K, I make a chamber, 7c, of such size andlength that the upper end of the stem p. with its fastening s', may haveashort range of motion therein in a vertical direction, the maximumlength of such motion being, by preference, equal, or nearly equal, tothe maximum length of motion of the valve e. l

In Fig. 2 I have shown the relative position of the valves when thebrakes are ot'f and The valves then are all seated. Ordinarily thescrewplug S will be turned up a little from what is there shown, sincethe spring s2, as here represented, is under partial compression, aswill presently be explained.

When, now, the engineer desires to apply the brakes, he operates thecrank S so as to screw the plug S downwardly much or little, accordingas he may desire to apply the brakes with much or little force. motionof thev plug S is communicated through the spring s2 to the piston P,and through its stem p to the stem c of the valve e, so as to unseat thelatter, as shown in Fig. l. Fluidpressure from the boiler then passesfrom B to B2 and on to the brake-cylinders, and is there operative inapplying the brakes in the usual way. The steam-pressure also passesfreely along the stems from a to a? below the piston P, so that thevalve D4 will be held to its seats, not only by its own weight, but alsoby a preponderance or excess of pressure on its upper and larger end.rIhus the escape is kept closed. rlhe engineer in this way opens thevalve e, so as to admit much or little tiuidpressure, as hc may desire,and he regulates the amount of such pressure by the amount ot'port-opening which he makes in shifting the valve c off its seat, or, inother words, by the length of motion imparted to the valve e. Assumingit to be shifted from -its seat in Fig. l a distance which will giveone-halt' the maximum'port-opening, the operation will be as abovedescribed, but with this additional element, viz the steam passingfreely into the chamber a2 below the piston-head P will act rlhisdownward with the same pressure there as in the brakecylinders. As soonas the desired or predetermined amount of pressure has thus passedthrough the port-opening ofthe unseated valve e, any excess of suchpressure acting on the under side of the piston-head P will compress thespring s2, and thereby raise P, and with it the stem p p', and therebypermit the valve c to be forced to its seat. Also, it will be observedthat the spring e2, which is beneath the valve e, co-opcrates in givingthis motion to the piston-head P, and the cessation of such force whenthe valve e comes to its seat and the increased resistance of the springs2 as it is compressed result in the stoppage of the upward motion ofthe piston-head yP as soon as the valve c is seated. Hence the forces soacting will be insufficient to carry the pistonstem pp high enough tounseat the escapevalve D4. The position ot' the devices will then bethat shown in Fig. 2. The brakes will then be held on without increaseor diminution ofthe fluid-pressure except by leakage or condensation,and as soon as this becomes appreciable the Ydiminution of the pressureunder theV piston-head P will permit the resiliency ot' the spring s2 tobecome operative in automatically opening the valve e to such extent asto supply such loss; or if the engineer desires a little additionalbrake-power,

- he turns the screw-plug S a little farther down,

so as to give an additional opening to theport ofthe valve e andincrease the fluid-pressure necessary to recompress the spring s2 andreseat the valve e; and such increase of power will be operative asbrake-power before it again acts to raise the }')isto1'1-head I and stemp', and thereby permit the valve e again to resulne its seat. In thisway the supply is automatically cut o and the effective Huid-pressureoperative in braking is retained, and such eut-oft' function isperformed as soon as the desired or predetermined amount of iuidpressurerequired for braking purposes has been attained; and the amount of suchforce may be augmented at any time without danger of opening the exhaustor discharge valve.

When the engineer desires to release the brake he screws the plug S upor outand brings the washer a against the lower end ofthe valve D4, andthereby lifts the valve clear of its seats. All the uidpressure (inexcess ot' atmospheric pressure) which has passed the valve e has then afree escape into the external atmosphere,so that the brakes will be ob",and in order the better to facilitate the escape of the steam from thechamber a2, I provide a series of ports, t', leading from the inside ofthe valve D* to its outside, but above the washer a. rIhe entirebraking-power may thus be allowed to escape, or only a part, as may bepreferred. Screwing the plug S down again will again result in theclosing of all the valves. But for the purpose of partially releasingthe brakes, or lessening the effective brake-power, the valve D4 may besli ght-ly raised, and, as soon as the pressure is 222,503 t l Y asufficiently reduced, be reseated inthe manner described; but the sameresult may also be secured (say when the devices are in the positionshown in Fig. 2 and the brakes are on) by slight-ly slackening up orunscrewing the plug S, so that the piston-head P, being held down by aless degree of spring-pressure, may be raised slightly by excess offluid-pressure below, and thereby slightly raise the valve D4. Then, assoon as the pressure has been reduced below that exerted by the spring,the latter will force the piston-head P down `and cause the valve D4 toresume its seat.

As some steam will be likely to leak past the packing of the piston-headP, I provide for carrying it off by a pipe, I).

It will now be seen that I provide for operating both the supply andt-he exhaust valves by a single stern, that only one can be opened atonce, that either may be opened separately, (much or little,) and thatboth may be closed simultaneously and automatically, and kept closedwhether the brakes are on or off.

Any suitable index-marks or pressure-gage may be employed, it' sodesired, to guide the engineer in giving to the crank-arm the properlength of motion or admitting the proper pressure with reference tosecuring the proper charging of the brake-power into the brakecylinders5 and while the device described is particularly designed for use as anoperatingcock for steam-brakes, it may, with like utility and in likemanner, be used for like functions in other huid-pressure brakes. Theusual drain devices may be supplied.

i It should be added that the elasticityor compressibility of the springs2 should, either in its manufacture or adjustment, or in bot-h, be suchor so regulated that it will work in the manner above describedthat isto say, that it may be relied on to open or unseat the valve e; but whenthe valve is but slightly open it will be compressed by a comparativelylight steampressure, so as to allow the valve to be closed, and as thethrow of the valve e is increased an increased amount of steam-pressurewill be required to compress it, 4so as to let the valve close. Thus thelength of the throw of the valve will automatically regulate the amountof brake-power applied.

Relative terms, such as above, below,7 under, etc., are herein used intheir relative sense, so that the inversion of the device .would not bea material change as regards the invention described herein.

Mechanical equivalents also may be substituted for any or all thedevices specied-as, for example, a double-ended piston-valve workin g ina cylindrical ported chamber may take the place ofthe valve D, and alsoother suitable means, such as a plunger, may be employed for giving tothe stem p the described motions.

I claim hereinas myinventionl.' The valve e and its ported diaphragm,opened and closed by an endwise-abuttin g ste-1n, p', in combinationwwith double-seated valve D4, arranged on such stem, a system ofescape-ports leading from between the seats to the external air, and aconnection from the stem with such valve, whereby the latter may beunseated after the former valve has been seated, substantially as setforth.

2. As a means for automatically cutting ot't' the fluid-pressure supply`when the desired pressure has been charged into the brakecylinders, apiston-head, I), movable by the operative brake=pressure or any excessthereof, in combination with the charging-valve and a connection fromone to the other, substantially as set forth, whereby such movement ofthe piston-head will result inthe automatic closing of thecharging-valve, substantially as set forth.

3. Thccombination of piston-head, charging-` valve, interposed stem,'andescape-valve, substantially as set forth with reference to the openingand closing of the charging-valve, without necessarily opening theescape-valve, substantially as set forth. i

4. The'coipbination of piston-head, charging-valve, interposed stem,escape-valve, and

a single operating'- stem, adapted by independent connections with bothvalves to shift both by independent successive motions, substantially asset forth.

5. A fluid-pressure brake-charging valve opened by a positive butvariable mechanical force acting through an interposed spring, andautomatically relieved of the force which opened it by the duid-pressureitself acting to compress such spring, substantially as set forth.

6. An operating cock for fluid-pressure brakes, having, in combination,a spring subject to positive but variable mechanical pressure in onedirection, and, by a piston, subject to a variable duid-pressure in theother direction, a supply or charging valve opened by the positivemotion imparted to the spring and closed by the action of thefluid-pressure, and a discharging or exhaustvalve held toits seat byduid-pressure whilethe'brakes are on, but raised from its seat onlyafter the chargingport is closed, substantially as set forth.

7. The double-seated exhaust or dischargingvalve D4, playing freely onthe stem p' within the necessary range of motion for opening and closingthe supply-valve e, whereby, in opening and closing the supply-valve,the discharging-valve retains its seats, in combination with a system ofexhaust-ports between the seats, and a ring, collar, r catch, fn', ou

the stem p', arranged to unseat the dischargevalve after thesupply-valve is closed, substantially as set forth.

In testimony whereof I have hereunto set my hand. GEGRGE WESTINGHOUSE,JR. Witnesses:

1t. H. Wnrr'rnnsnv, C. L. PARKER.

